U.S. patent application number 11/567918 was filed with the patent office on 2007-08-02 for fuel tank for a motor vehicle.
This patent application is currently assigned to KAUTEX TEXTRON GmbH & Co. KG. Invention is credited to Klaus Wolfgang Gebert, Thomas Schaefer.
Application Number | 20070175524 11/567918 |
Document ID | / |
Family ID | 37682788 |
Filed Date | 2007-08-02 |
United States Patent
Application |
20070175524 |
Kind Code |
A1 |
Gebert; Klaus Wolfgang ; et
al. |
August 2, 2007 |
FUEL TANK FOR A MOTOR VEHICLE
Abstract
The invention concerns a fuel tank for a motor vehicle,
comprising at least one venting device which is connected to a fuel
vapor filter, wherein the venting device includes at least one
collecting container (4) for receiving liquid fuel (21). The fuel
tank is distinguished in that disposed within the collecting
container (4) is a delivery pump (8) for emptying it into the
delivery volume (23) of the fuel tank (1).
Inventors: |
Gebert; Klaus Wolfgang;
(Willich, DE) ; Schaefer; Thomas; (Bonn,
DE) |
Correspondence
Address: |
GROSSMAN, TUCKER, PERREAULT & PFLEGER, PLLC
55 SOUTH COMMERICAL STREET
MANCHESTER
NH
03101
US
|
Assignee: |
KAUTEX TEXTRON GmbH & Co.
KG
Bonn
DE
|
Family ID: |
37682788 |
Appl. No.: |
11/567918 |
Filed: |
December 7, 2006 |
Current U.S.
Class: |
137/565.22 ;
123/516 |
Current CPC
Class: |
Y10T 137/86075 20150401;
B60K 15/03504 20130101; B60K 2015/03509 20130101 |
Class at
Publication: |
137/565.22 ;
123/516 |
International
Class: |
F02M 37/20 20060101
F02M037/20; B01D 47/02 20060101 B01D047/02 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 7, 2005 |
DE |
10 2005 058 617.1 |
Claims
1. A fuel tank for a motor vehicle, comprising at least one venting
device which is connected to a fuel vapor filter, wherein the
venting device includes at least one collecting container for
receiving liquid fuel, characterised in that disposed within the
collecting container is a delivery pump for emptying it into the
delivery volume of the fuel tank.
2. A fuel tank as set forth in claim 1 characterised in that the
delivery pump is driven by way of at least one fan wheel which is
so arranged that it can be caused to rotate by the venting flow
which is passed through the collecting container.
3. A fuel tank as set forth in claim 2 characterised in that the
fan wheel is arranged with a pump impeller of the delivery pump on
a common shaft.
4. A fuel tank as set forth in claim 1 characterised in that the
delivery pump is in the form of a side passage pump.
5. A fuel tank as set forth in claim 1 characterised in that the
fan wheel is arranged within a housing having an inner portion and
an outer portion, that the inner portion forms a core tube portion
which encloses the fan wheel and that the outer portion forms a
casing tube portion which with the core tube portion forms a
suction intake gap which narrows in the flow direction of the
venting flow.
6. A fuel tank as set forth in claim 5 characterised in that the
outer portion is in the form of a bowl which enlarges conically in
the flow direction and whose bottom has the shaft of the fan wheel
and the pump impeller respectively passing therethrough.
7. A fuel tank as set forth in claim 1 characterised in that the
delivery pump is connected with its pressure side to an outlet
opening of the collecting container, which outlet opening
communicates with the fuel tank.
8. A fuel tank as set forth in claim 1 characterised in that the
collecting housing comprises two chambers which communicate with
each other by way of an overflow opening, that a first chamber is
provided as a liquid collecting space and a second chamber is
provided as a gas collecting space, the overflow opening is
closable by a filling level-switched valve and the delivery pump is
so connected that closure of the overflow opening causes a rise in
pressure in the liquid collecting space so that emptying thereof
occurs by way of an outlet opening into the delivery volume of the
fuel tank.
9. A fuel tank as set forth in claim 8 characterised in that the
delivery pump is connected at the suction side to the gas
collecting space.
10. A fuel tank as set forth in claim 1 characterised in that the
delivery pump and the drive thereof are combined to form one unit.
Description
[0001] The invention concerns a fuel tank for a motor vehicle,
comprising at least one venting device which is connected to a fuel
vapor filter, wherein the venting device includes at least one
collecting container for receiving liquid fuel.
[0002] A fuel tank of that kind is known for example from EP 1 196
303 B1. The fuel tank known from EP 1 196 303 includes means for
venting same when refueling the tank and in operation of the motor
vehicle. The venting lines are connected in known manner by way of
a collecting container to a pressure compensating line connected to
an activated carbon filter.
[0003] When filling the fuel tank with fuel the gas present in the
tank is displaced by the incoming flow of liquid. So that no
hydrocarbons are discharged to the atmosphere in the refueling
operation, the gas volume flow which is displaced in the refueling
operation is usually discharged to the atmosphere by way of a fuel
vapor filter. The gases which are produced in operation of the
motor vehicle as a result of evaporation of the fuel are also
discharged to the atmosphere in a cleaned form by way of the fuel
vapor filter.
[0004] The activated carbon in the fuel vapor filter may not be
wetted with liquid hydrocarbons, such wetting would detrimentally
affect the adsorptive properties of the activated carbon. For that
reason it is known for collecting containers or beading-out
containers to be disposed upstream of the fuel vapor filter in the
venting lines. Any condensate which is produced as well as
entrained liquid hydrocarbon particles are deposited out in the
collecting container and added to the delivery volume of the fuel
tank again in a suitable fashion.
[0005] Collecting containers of that kind are arranged in part
outside the fuel tank and in part within it.
[0006] To avoid potential emission and leakage points, for example
EP 1 196 303 proposes arranging such a collecting container within
the fuel tank so that it is possible to dispense with the
arrangement of lines which communicate the internal space of the
fuel tank with the collecting container.
[0007] A further advantage of a collecting container which is
disposed within the fuel tank is that it cannot tear away in the
event of the motor vehicle crashing as the collecting container is
arranged in a protected condition within the fuel tank.
[0008] It is readily understandable that the liquid fuel which
occurs in the collecting container or beading-out container must be
returned again to the delivery volume of the fuel tank. That can be
easily effected for example by means of the force of gravity
through a drain opening provided with a valve in the collecting
container.
[0009] Depending on the respective pressure conditions in the fuel
tank and depending on the respective position of installation of
the collecting container, emptying thereof by virtue of the effect
of the force of gravity is not always effectively possible.
[0010] Therefore EP 1 196 303 B1 proposes connecting the collecting
container to the suction side of a suction jet pump present in the
fuel tank. The suction jet pump can be operated for example by the
return flow of fuel from the engine in operation of the motor
vehicle. That effectively provides that the collecting container is
sucked out.
[0011] Such an arrangement however suffers from the disadvantage
that additional lines have to be placed within the fuel tank, which
means that in particular the assembly complication and expenditure
in completing the fuel tank becomes comparatively high.
[0012] Therefore the object of the invention is to develop a fuel
tank of the kind set forth in the opening part of this
specification in such a way that effective emptying of the
collecting container can be effected with means of the utmost
simplicity.
[0013] That object is attained by the features of claim 1.
[0014] Advantageous configurations of the invention are set forth
in the appendant claims.
[0015] The fuel tank according to the invention is distinguished in
that disposed within the collecting container is a delivery pump
for emptying it into the delivery volume of the fuel tank. In other
words, the delivery pump for actively emptying the collecting
container is completely integrated therein so that line connections
for connecting same to a pump arranged outside it are unnecessary.
That is advantageous in particular for the reason that mounting
installation fitments in the fuel tank can generally only be
effected through one or more inspection openings, the size of which
is such that it is possible to pass thereinto with the hand, but it
will be noted that in that case the assembly procedure has to be
carried out without being able to view it. Accordingly that
involves additional complication and expenditure for each line
which is to be laid and clipped in the tank, the suction jet pump
or the like. Finally it is necessary for such lines, as already
indicated hereinbefore, to be fixed to the tank wall. In that
respect the solution according to the invention represents a
substantial simplification in terms of assembling the fuel
tank.
[0016] It is particularly desirable if the delivery pump is driven
by way of at least one fan wheel which is so arranged that it can
be caused to rotate by the venting flow which is passed through the
collecting container. In a particularly advantageous variant of the
fuel tank according to the invention therefore the drive for the
delivery pump is in the form of an axial turbine which utilises the
venting volume flow during refueling and in operation. In
particular so-called `on board fuel vapor recovery` systems which
are wide-spread on the American market are suitable for that
purpose. In that case the gas volume flow which is produced in the
refueling operation is passed for the major part by way of the fuel
vapor filter, and the filling opening of the fuel tank is sealed
off in relation to the refueling gun during the refueling
procedure.
[0017] Desirably, the fan wheel is arranged with a pump impeller of
the delivery pump on a common shaft.
[0018] The delivery pump can be for example in the form of a side
passage pump. Side passage pumps have the advantage that they are
of a particularly compact size and have few moving parts.
[0019] A variant of the fuel tank according to the invention
provides that the fan wheel is arranged within a housing having an
inner portion and an outer portion, that the inner portion forms a
core tube portion which encloses the fan wheel and that the outer
portion forms a casing tube portion which with the core tube
portion forms a suction intake gap which narrows in the flow
direction of the venting flow.
[0020] That arrangement provides that the venting flow which drives
the fan wheel is accelerated within the housing or within the
suction intake gap so that particularly effective utilisation of
the kinetic energy of the gas flow is guaranteed.
[0021] Desirably the outer portion is in the form of a bowl which
enlarges in the flow direction and whose bottom has the shaft of
the fan wheel and the pump impeller respectively passing
therethrough. The arrangement in that case is so selected that the
gas inlet and the gas outlet from the housing are arranged on one
side thereof.
[0022] The delivery pump can be connected for example with its
pressure side to an outlet opening of the collecting container,
which outlet opening communicates with the fuel tank. The outlet
opening can be closed with a non-return valve.
[0023] In an alternative configuration of the fuel tank according
to the invention the collecting housing comprises two chambers
which communicate with each other by way of an overflow opening,
wherein a first chamber is provided as a liquid collecting space
and a second chamber is provided as a gas collecting space, the
overflow opening is closable by a filling level-switched valve and
the delivery pump is so connected that closure of the overflow
opening causes a rise in pressure in the liquid collecting space so
that emptying thereof occurs by way of an outlet opening into the
delivery volume of the fuel tank. In this variant of the
configuration of the collecting container the fuel in the liquid
collecting space is not conveyed directly by way of the delivery
pump, but rather the delivery pump serves only to increase the
pressure and thus to provide for indirect emptying of the liquid
collecting space when a certain level of liquid is attained
therein.
[0024] In this embodiment of the invention the delivery pump can be
connected at the suction side to the gas collecting space. The
suction side of the pump can alternatively also be connected to the
delivery volume of the fuel tank Desirably the delivery pump and
the drive thereof are combined to form one unit.
[0025] The invention is described hereinafter by means of an
embodiment by way of example illustrated in the drawings in
which:
[0026] FIG. 1 is a diagrammatic view of the fuel tank according to
the invention,
[0027] FIG. 2 is a sectional view on an enlarged scale through the
collecting container shown in FIG. 1 in accordance with a first
embodiment of the invention, and
[0028] FIG. 3 shows a view in section of an alternative
configuration of the collecting container
[0029] The fuel tank 1 shown in FIG. 1 includes in known manner a
filler pipe 2 and means (not shown) for conveying and removing fuel
for delivery thereof as well as means for introducing air into and
venting the fuel tank 1 during refueling and operation. In general
the fuel tank 1 is for example in the form of a plastic tank which
was produced in one piece by extrusion blow molding. It can be of a
comparatively complicated, chamber-like structure involving various
sub-volumes The fuel tank 1 shown in FIG. 1 is illustrated in a
greatly simplified form for the purposes of enhanced clarity.
[0030] For the purposes of venting the fuel tank in a refueling
operation or in operation, provided in the fuel tank are various
ventilation points which can each be controlled with respective
valves. From the valves venting lines 3 are taken by way of a
collecting container 4 to a fuel vapor filter (activated carbon
filter) (not shown).
[0031] For that purpose the collecting container 4 shown in the
Figures is connected to an operational venting line identified by
reference 3b and a refueling venting line identified by reference
3a. Reference 5 denotes the pressure compensating line which is
passed from the fuel tank 1 to an activated carbon filter. Also
provided on the collecting container 4 is a drain opening 6 which
is closed by a non-return valve 7.
[0032] The dimensional relationships of the lines 3, 5 shown in
FIGS. 2 and 3 do not allow any conclusions at all to be drawn about
their actual dimensioning in relation to each other. FIGS. 2 and 3
are also highly simplified diagrammatic views.
[0033] Reference is firstly made to FIG. 2 in which the collecting
container 4 is shown in section on an enlarged scale. Arranged
therein is a delivery pump 8 for emptying it, together with an
associated drive 9. As will be further described hereinafter, the
drive 9 is in the form of an axial turbine which is driven by way
of the venting volume flow or by way of the carbon-enriched gas
which is passed through the collecting container 4 in the venting
operation.
[0034] The delivery pump 8 is in the form of a side passage pump
which is known per se and whose pump impeller 10 is arranged on a
common shaft 12 with a fan wheel 11 which belongs to the drive. The
fan wheel 11 in turn is arranged in a two-part housing, wherein the
housing includes an outer portion 14 and an inner portion 15. The
outer portion 14 forms a casing tube and is of an approximately
bowl-shaped configuration and enlarges conically at its side remote
from the pump impeller 10. The shaft 12 passes through the bottom
16 of the outer portion 14 which forms the functional separation
between the drive 9 and the pump. The tube-shaped inner portion 15
which encloses the fan wheel 11 is arranged within the outer
portion 4 in such a way that a suction intake gap 17 which narrows
conically in the flow direction is formed between the inner portion
15 and the outer portion 14.
[0035] Due to the reduction in cross-section of the suction intake
gap 17 the gas flow experiences an acceleration effect. At the
bottom 16 of the outer portion 14 the gas flow is finally deflected
and passed axially through the inner portion 15 where it causes the
fan wheel 11 to be driven. The fan wheel 11 in turn rotates the
shaft 12 and therewith the pump impeller 10. The pump impeller 10,
with the pump housing 18, forms a side passage 19 which in known
manner is arranged to extend in a spiral configuration and connects
an inlet opening 20 (suction side) and an outlet opening 21
(pressure side) of the delivery pump 8.
[0036] When refueling the motor vehicle the gas volume flow which
flows in through the refueling venting line 3a drives the fan wheel
11 and therewith also the pump impeller 10. The liquid fuel 22
which is only illustrated by way of indication is sucked in through
the inlet opening 20 and pumped through the outlet opening 21
against the non-return valve 7 into the delivery volume 23 of the
fuel tank 1.
[0037] Reference is now made to the embodiment shown in FIG. 3 of
the collecting container 4 which is subdivided by an intermediate
wall 24 into two chambers, wherein a first chamber is in the form
of a liquid collecting space 25 and a second chamber is in the form
of a gas collecting space 26 or a gas inflow chamber.
[0038] In the embodiment illustrated in FIG. 3, identical
components are denoted by the same references.
[0039] The unit consisting of the delivery pump 8 and the drive 9
passes through the intermediate wall 24 of the collecting container
4, with the outer portion 14 being sealed off with respect to the
intermediate wall 24. Reference 27 denotes a suction intake snorkel
which is connected to the inlet opening 20 of the delivery pump 8
and which also passes through the intermediate wall 24 and
communicates with the gas collecting space 26. Also provided in the
intermediate wall 24 is an overflow opening 28 by way of which the
gas collecting space 26 and the liquid collecting space 25
communicate with each other as long as the level of the liquid fuel
22 in the liquid collecting space 25 does not exceed a certain
height. The overflow opening 28 is closable by means of a float
valve 29 when a given filling level is exceeded, in which case the
valve body 30 is lifted by the fuel 22 and closes the overflow
opening 28.
[0040] Particularly in a refueling operation, the incoming gas
volume flow which is passed by way of the pressure compensating
line 5 to the activated carbon filter (not shown) drives the fan
wheel 11 and therewith the pump impeller 10 of the delivery pump 8.
The delivery pump 8 draws gas out of the gas collecting space 26
into the liquid collecting space 25 by way of the snorkel 27. As
the gas collecting space 26 and the liquid collecting space 25
communicate with each other, the delivery pump 18 is operating
virtually in a no-load mode. The condensed or beaded-out fuel 22
collects in the liquid collecting space 25 until the valve body 30
floats up and closes the overflow opening 28. That causes the
delivery pump 8 to produce a pressure rise in the liquid collecting
space 25, which causes emptying of the liquid collecting space 25
against the closing force of the non-return valve 7. The non-return
valve 7 is in the form of a flutter valve with an elastomer disk as
the closure body so that the closing force thereof is comparatively
moderate.
LIST OF REFERENCES
[0041] 1 fuel tank [0042] 2 filler pipe [0043] 3 venting lines
[0044] 3a refueling venting line [0045] 3b operational venting line
[0046] 4 collecting container [0047] 5 pressure compensating line
[0048] 6 drain opening [0049] 7 non-return valve [0050] 8 delivery
pump [0051] 9 drive [0052] 10 pump impeller [0053] 11 fan wheel
[0054] 12 shaft [0055] 13 housing [0056] 14 outer portion [0057] 15
inner portion [0058] 16 bottom of the outer portion [0059] 17
suction intake gap [0060] 18 pump housing [0061] 19 side passage
[0062] 20 inlet opening [0063] 21 outlet opening [0064] 22 liquid
fuel [0065] 23 delivery volume [0066] 24 intermediate wall [0067]
25 liquid collecting space [0068] 26 gas collecting space [0069] 27
snorkel [0070] 28 overflow opening [0071] 29 float valve [0072] 30
valve body
* * * * *